Compliance against the fire effect over the aircraft is one of the items required to obtain aircraft certification.
In the aircraft there are a number of designated fire zones which shall be able to withstand the effect of an applied fire for a period of time given according to the zone category requirements and without having a detrimental effect on the aircraft performances outside a predetermined margin.
The different categories according to the fire resistance are as follows:                Areas which not require to be able to withstand the effect of a fire.        Fire resistance areas. Zones affected by this classification shall be able to withstand the effect of a standard flame for 5 minutes.        Fire proof areas. Zones affected by this classification shall be able to withstand the effect of a standard flame for 15 minutes.        
Generally speaking engine and auxiliary power unit compartment are designated fire areas. Those areas are the ones where flammable mixtures can be expected to occur as a result of a fault causing spillage or leakage and where an explosive environment may occur, therefore they shall be demonstrated to as fire proof under different requirements:                Areas required to withstand the application of a flame and to put up with the loads imposed by the design.        Areas required to withstand the application of a flame without flame penetration.        
Typically, the compliance against those requirements was demonstrated by physical tests.
This procedure is very costly and the present invention is intended to solve this drawback.